From: "Mattias Engdegård" <mattiase@acm.org>
To: Michael Albinus <michael.albinus@gmx.de>
Cc: 35418@debbugs.gnu.org
Subject: bug#35418: [PATCH] Don't poll auto-revert files that use notification
Date: Tue, 14 May 2019 14:41:14 +0200 [thread overview]
Message-ID: <f55c9ca54bf77ccdddf7b4fb86c231f904e6a6f9.camel@acm.org> (raw)
In-Reply-To: <871s12jx40.fsf@gmx.de>
[-- Attachment #1: Type: text/plain, Size: 360 bytes --]
mån 2019-05-13 klockan 15:35 +0200 skrev Michael Albinus:
>
> Do we want to say that this is related to a major mode in general?
> That
> means, that the mode function shall set this variable. And do we want
> to
> mention dired-mode as example?
Good point, paragraph changed.
> Same remark. Mention major mode dependency.
Done.
Updated patch attached.
[-- Attachment #2: 0001-Don-t-use-file-notification-on-non-file-buffers.patch --]
[-- Type: text/x-patch, Size: 5380 bytes --]
From efda86ef03befb73356c7b23ee21e7d9efd8b181 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Wed, 8 May 2019 00:02:59 +0200
Subject: [PATCH] Don't use file notification on non-file buffers
Most non-file buffers aren't served by file notification in
auto-revert mode; typically, they need to be polled, like the Buffer List.
With `auto-revert-avoid-polling', setting a useless notification means
that such buffers may never be updated at all (bug#35418).
Non-file buffers can explicitly declare that notification on their
default-directory is sufficient to know when updates are required
by setting the new variable `buffer-auto-revert-by-notification' to
a non-nil value.
* lisp/autorevert.el (auto-revert-buffers):
Modify condition for using notification.
* lisp/files.el (buffer-auto-revert-by-notification): New variable.
* lisp/dired.el (dired-mode): Set buffer-auto-revert-by-notification.
* doc/emacs/arevert-xtra.texi (Non-File Buffers): Document new variable.
* etc/NEWS (Changes in Specialized Modes and Packages): Describe new variable.
---
doc/emacs/arevert-xtra.texi | 8 ++++++++
etc/NEWS | 7 +++++++
lisp/autorevert.el | 6 +++++-
lisp/dired.el | 1 +
lisp/files.el | 10 ++++++++++
5 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/doc/emacs/arevert-xtra.texi b/doc/emacs/arevert-xtra.texi
index 9e01a10ace..37e2f9e581 100644
--- a/doc/emacs/arevert-xtra.texi
+++ b/doc/emacs/arevert-xtra.texi
@@ -35,6 +35,14 @@ Non-File Buffers
messages while reverting, even when @code{auto-revert-verbose} is
non-@code{nil}.
+@vindex buffer-auto-revert-by-notification
+Some non-file buffers can be updated reliably by file notification on
+their default directory; Dired buffers is an example. The major mode
+can indicate this by setting @code{buffer-auto-revert-by-notification}
+to a non-@code{nil} value in that buffer, allowing Auto Revert to
+avoid periodic polling. Such notification does not include changes to
+files in that directory, only to the directory itself.
+
The details depend on the particular types of buffers and are
explained in the corresponding sections.
diff --git a/etc/NEWS b/etc/NEWS
index 43ad8be1cc..57ef76614f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1428,6 +1428,13 @@ of an idle Emacs, but may fail on some network file systems; set
notification is not supported. The new variable currently has no
effect in 'global-auto-revert-mode'. The default value is nil.
+*** New variable 'buffer-auto-revert-by-notification'
+A major mode can declare that notification on the buffer's default
+directory is sufficient to know when updates are required, by setting
+the new variable `buffer-auto-revert-by-notification' to a non-nil
+value. Auto Revert mode can use this information to avoid polling the
+buffer periodically when 'auto-revert-avoid-polling' is non-nil.
+
\f
* New Modes and Packages in Emacs 27.1
diff --git a/lisp/autorevert.el b/lisp/autorevert.el
index 7cd5e7ee8b..197a2bf157 100644
--- a/lisp/autorevert.el
+++ b/lisp/autorevert.el
@@ -858,8 +858,12 @@ auto-revert-buffers
(auto-revert-remove-current-buffer))
(when (auto-revert-active-p)
;; Enable file notification.
+ ;; Don't bother creating a notifier for non-file buffers
+ ;; unless it explicitly indicates that this works.
(when (and auto-revert-use-notify
- (not auto-revert-notify-watch-descriptor))
+ (not auto-revert-notify-watch-descriptor)
+ (or buffer-file-name
+ buffer-auto-revert-by-notification))
(auto-revert-notify-add-watch))
(auto-revert-handler)))))
(setq bufs (cdr bufs)))
diff --git a/lisp/dired.el b/lisp/dired.el
index 385126514b..ea1943de1d 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2148,6 +2148,7 @@ dired-mode
(setq buffer-invisibility-spec (list t)))
(setq-local revert-buffer-function #'dired-revert)
(setq-local buffer-stale-function #'dired-buffer-stale-p)
+ (setq-local buffer-auto-revert-by-notification t)
(setq-local page-delimiter "\n\n")
(setq-local dired-directory (or dirname default-directory))
;; list-buffers uses this to display the dir being edited in this buffer.
diff --git a/lisp/files.el b/lisp/files.el
index 8477c227bc..becb5aab6f 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -5843,6 +5843,16 @@ buffer-stale-function
For more information on how this variable is used by Auto Revert mode,
see Info node `(emacs)Supporting additional buffers'.")
+(defvar-local buffer-auto-revert-by-notification nil
+ "Whether a buffer can rely on notification in Auto-Revert mode.
+If non-nil, monitoring changes to the directory of the current
+buffer is sufficient for knowing when that buffer needs to be
+updated in Auto Revert Mode. Such notification does not include
+changes to files in that directory, only to the directory itself.
+
+This variable only applies to buffers where `buffer-file-name' is
+nil; other buffers are tracked by their files.")
+
(defvar before-revert-hook nil
"Normal hook for `revert-buffer' to run before reverting.
The function `revert-buffer--default' runs this.
--
2.20.1
next prev parent reply other threads:[~2019-05-14 12:41 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 18:14 bug#35418: [PATCH] Don't poll auto-revert files that use notification Mattias Engdegård
2019-04-24 18:58 ` Eli Zaretskii
2019-04-24 19:36 ` Michael Albinus
2019-04-26 20:46 ` Mattias Engdegård
2019-04-27 9:40 ` Michael Albinus
2019-04-27 16:28 ` Mattias Engdegård
2019-04-25 9:56 ` Mattias Engdegård
2019-04-25 10:04 ` Eli Zaretskii
2019-04-25 18:07 ` Mattias Engdegård
2019-04-27 9:27 ` Michael Albinus
2019-04-27 9:54 ` Eli Zaretskii
2019-04-27 10:23 ` Michael Albinus
2019-04-27 16:19 ` Mattias Engdegård
2019-04-27 16:52 ` Eli Zaretskii
2019-04-28 10:21 ` Mattias Engdegård
2019-04-29 7:53 ` Michael Albinus
2019-04-29 11:06 ` Mattias Engdegård
2019-04-29 12:18 ` Michael Albinus
2019-04-29 16:24 ` Eli Zaretskii
2019-04-29 18:29 ` Mattias Engdegård
2019-04-29 20:17 ` Michael Albinus
2019-04-30 3:57 ` Eli Zaretskii
2019-04-30 11:41 ` Mattias Engdegård
2019-04-30 12:59 ` Michael Albinus
2019-04-30 13:56 ` Mattias Engdegård
2019-04-30 14:19 ` Michael Albinus
2019-04-29 16:23 ` Eli Zaretskii
2019-04-29 19:21 ` Mattias Engdegård
2019-04-29 19:56 ` Michael Albinus
2019-04-30 21:09 ` Mattias Engdegård
2019-05-01 17:45 ` Eli Zaretskii
2019-05-01 19:41 ` Mattias Engdegård
2019-05-02 12:18 ` Michael Albinus
2019-05-02 12:53 ` Mattias Engdegård
2019-05-02 13:02 ` Michael Albinus
2019-05-03 12:00 ` Mattias Engdegård
2019-05-03 13:44 ` Eli Zaretskii
2019-05-03 14:47 ` Mattias Engdegård
2019-05-04 9:04 ` Eli Zaretskii
2019-05-04 11:21 ` Mattias Engdegård
2019-05-04 13:41 ` Eli Zaretskii
2019-05-04 16:53 ` Michael Albinus
2019-05-04 17:08 ` Eli Zaretskii
2019-05-04 18:50 ` Mattias Engdegård
2019-05-04 19:43 ` Michael Albinus
2019-05-04 20:31 ` Michael Albinus
2019-05-04 20:46 ` Mattias Engdegård
2019-05-05 8:22 ` Michael Albinus
2019-05-05 9:58 ` Mattias Engdegård
2019-05-08 8:34 ` Mattias Engdegård
2019-05-08 8:47 ` Eli Zaretskii
2019-05-08 10:18 ` Mattias Engdegård
2019-05-08 10:58 ` Eli Zaretskii
2019-05-08 11:48 ` Mattias Engdegård
2019-05-08 12:35 ` Eli Zaretskii
2019-05-08 12:58 ` Mattias Engdegård
2019-05-08 13:09 ` Michael Albinus
2019-05-08 13:28 ` Eli Zaretskii
2019-05-08 14:13 ` Mattias Engdegård
2019-05-08 17:24 ` Eli Zaretskii
2019-05-08 18:17 ` Michael Albinus
2019-05-09 11:50 ` Michael Albinus
2019-05-10 15:22 ` Mattias Engdegård
2019-05-12 8:48 ` Michael Albinus
2019-05-12 19:49 ` Mattias Engdegård
2019-05-13 13:35 ` Michael Albinus
2019-05-14 12:41 ` Mattias Engdegård [this message]
2019-05-14 14:52 ` Michael Albinus
2019-05-08 10:23 ` Mattias Engdegård
2019-05-09 10:00 ` Mattias Engdegård
2019-05-09 10:48 ` Eli Zaretskii
2019-05-09 11:15 ` Mattias Engdegård
2019-05-10 9:49 ` Michael Albinus
2019-05-10 12:27 ` Mattias Engdegård
2019-05-10 12:43 ` Michael Albinus
2019-05-13 11:34 ` Mattias Engdegård
2019-05-13 15:08 ` Michael Albinus
2019-05-18 17:39 ` Mattias Engdegård
2019-05-19 9:12 ` Michael Albinus
2019-05-19 20:25 ` Mattias Engdegård
2019-05-20 7:30 ` Michael Albinus
2019-05-20 19:19 ` Mattias Engdegård
2019-04-29 7:19 ` Michael Albinus
2019-04-29 11:54 ` Mattias Engdegård
2019-04-29 12:26 ` Michael Albinus
2019-04-29 18:58 ` Mattias Engdegård
2019-04-29 20:04 ` Michael Albinus
2019-04-30 15:14 ` Eli Zaretskii
2019-04-24 19:59 ` Michael Albinus
2019-04-25 9:58 ` Mattias Engdegård
2019-04-25 11:04 ` Michael Albinus
2019-04-25 15:22 ` Mattias Engdegård
2019-04-30 1:03 ` Zhang Haijun
2019-04-30 7:06 ` Michael Albinus
2019-05-01 2:17 ` Zhang Haijun
2019-05-01 2:59 ` Zhang Haijun
2019-05-01 3:10 ` Zhang Haijun
2019-05-02 12:30 ` Michael Albinus
2019-05-02 13:24 ` Zhang Haijun
2019-05-02 12:28 ` Michael Albinus
2019-05-02 12:24 ` Michael Albinus
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